The present invention relates to processes for hydrocracking coal and other solid or liquid carbonaceous material. In such processes the carbonaceous material is heated to an elevated temperature of 1400.degree.-1800.degree. F. at pressures of 1500-2500 psi and contacted with hydrogen or other reducing gas to decompose large aromatic compounds to simpler hydrocarbons that can be conveyed as liquids or gases when used. Such processes produce a spectrum of products including alkanes and the aromatic compounds such as benzene, toluene, xylene, ethylbenzene, phenol and cresols. Although lignite and bituminous coal are important starting materials, various other solid and liquid carbonaceous materials including anthracite coal, wood, peat, oil shale, tar sand, lignin, solid and liquid petroleum residuals, and other related materials can be processed. In addition various liquids including anthracene, decalin, tars, bitumens, asphaltenes, condensed aromatics, derivatives of these materials, and other high boiling compounds may be advantageously processed by the method of this development.
Previous methods for hydrocracking high molecular weight carbonaceous materials have involved heating to an elevated temperature in the presence of hydrogen and maintaining the reactants at that temperature to produce lower molecular weight products. In most instances variation in the types of products and their relative concentrations was brought about by varying the reaction temperature at which the hydrocracking occurs. Such variations introduce difficult operating problems of managing heat balance requirements and waste heat recovery in plants that frequently change the spectrum of reaction products to meet different requirements such as for motor fuels or chemical feedstocks. For example a high concentration of phenol may be desirable in preparing a feedstock for phenolformaldehyde resins while other less odorous and deleterious aromatics such as benzene and xylenes may be desired for motor vehicle fuels. Research octane number (RON) is of considerable importance in preparing blending stock for internal combustion engine fuels. Solely from this consideration, phenols, cresols, xylenes, ethylbenzene and toluene are of considerable importance.